Muffler



2 Sheets-Sheet l W. C. MILES MUFFLER Filed July 11, 1956 INVENTOR.

Oct. 19, 1937.

W. C. MILES Oct. 19, 1937.

MUFFLER Filed July 11, 1936 2 Sheets-Sheet 2 IN VENTOR.

Patented Oct. 19, 1937 UNITED STATES PATENT OFFICE 36 Claims.

This invention relates to mufflers for use with internal combustionengines.

An important object of the invention is to provide an improved mufllerwhich is effective, efiicient, simple in construction, small in size,light in weight and inexpensive to manufacture.

Other objects and advantages of the invention will become apparent fromthe following description when taken in connection with the accompanyingdrawings, in which- Fig. 1 is a central, longitudinal, sectional view ofa muffler embodying one form of the invention.

Fig. 2 is an end elevation of the muffler as viewed from the left inFig. 1.

Fig. 3 is a transverse sectional view taken on line 3-3 of Fig. 1.

Fig. 4 is a transverse sectional view taken on line 4-4 of Fig. 1.

Fig. 5 is a central, longitudinal, sectional view of a modified form ofmuffler.

Fig. 6 is a fragmental, longitudinal, sectional view illustrating themanner in which a housing may be applied to the muffler of Fig. 5 forstreamlining purposes.

Fig. '7 is a central, longitudinal, sectional view of a modified form ofequalizing tube fitting.

Fig. 8 is an end elevation of the fitting of Fig. 7, and

Fig. 9 is a view showing the forward end of the fitting of Figs. 7 and 8as completely closed.

Referring particularly to Figs. 1 to 4, the numeral l0 indicates a sheetmetal casing, to opposite ends of which are suitably connected a pair ofheads II and I2. The heads II and I2 are provided, respectively, withflanged tube-receiving openings l4 and IS, the former of which isadapted to receive a coupling flange or tube l6 by which the mufiier maybe conveniently connected to the exhaust pipe of an internal combustionengine.

Disposed within the muffler casing is an equalizing unit I! whichfunctions to direct the exhaust gases through the muffler in such amanner that exhaust noises are eliminated to a very marked degreewithout substantially detracting from the normal efficiency of theengine under any and all operating conditions.

The above mentioned equalizing unit I! is constructed wholly of sheetmetal and includes an equalizing tube l8, about which is disposed acylindrical shell 20. The shell is held in a concentric relation to theequalizing tube l8 by a pair of end walls 2| and 22. These end walls aresubstantially frustro-conical in shape and are provided at theiropposite ends with flanges 24 and 25, the former of which are suitablyconnected, as by weldingyto opposite ends of the shell 20 and the latterof which embrace and are similarly connected to the equalizing tube l8.

To the forward end of the equalizing tube l8, there is connected afitting 26 which is of a shape similar to that of each of the end walls2| and 22. The larger end of the fitting 26 is formed with a flange 21which embraces and is welded to the forward end of the equalizing tubein an abutting relation to the flange of the adjacent end wall 2|.Within the smaller end of the fitting 26, there is disposed a deflectortube 28, having at one end a flange 30 which is welded to the inner wallof the fitting.

he equalizing unit I1 is held in a coaxial relation to the casing ID byreason of the fact that the equalizing tube [8 is supported at itsoutlet end by the head l2 and at its other end by a spider-likestructure 3|, which includes a ring 32, having a plurality of radiallydisposed weblike' arms 34, connected at their outer ends to the innerwall of the head I In order to insure the equalizing unit |l againstdisplacement with relation to the casing ID, the equalizing tube IB issuitably connected, as by welding, to the head |2 in the vicinity of theopening l5 thereof.

From the foregoing it will become apparent that the casing [0, theequalizing tube It and the shell 20 are so disposed with relation toeach other that the shell forms with the casing an annular feeder tubeor passage and with the equalizing tube a reservoir 36, which is closedat its opposite ends by the end walls 2| and 22.

In order that a path of communication may be afforded between the feedertube 35 and the equalizing tube |8 by way of the reservoir 36, the sidewall (shell 20) of the feeder tube and the side wall of the equalizingtube are provided with a plurality of slot-like ports 31 and 38, withwhich are associated deflecting lips 40 and 4|, respectively. As to theports 31 and 38, they may be readily formed by shearing the metal of thefeeder tube wall (shell 20) and the metal of the wall of the equalizingtube |8 at definitely lo cated intervals and depressing or distortingthe lip-forming metal adjacent such points of shearing, the desiredwidth and inclination, respectively, of the slot-like ports anddeflecting lips thus formed being easily obtainable by suitablyconstructed metal-working dies.

Referring to Fig. 5, wherein prime reference characters are employed toindicate elements already described in connection with Figs. 1 to 4, itwill be noted that the casing l0 and shell 20' are each frustro-conicaland that they,at their smaller ends, are substantially the same size asthe equalizing tube [8' to which the shell is directly connected and towhich the casing is indirectly connected by a collar 42 which is weldedto the equalizing tube and to which the casing is similarly secured.

Aside from the structural features just described which difierentiatethe muflier of Fig. 5

from the muffler of Figs. 1 to 4, the two mufflers are substantiallyidentical except that the equalizing tube [8' is closed at its forwardend by a fitting 44. As to the fitting 44, it will be observed that itis secured to the equalizing tube H3 in the manner in which the fitting26 is secured to the equalizing tube l8 (Fig. 1), but that it differsfrom the fitting 26 in that its inclined wall terminates in aconcave-convex bottom 45 by which direct communication between theequalizing tube l8 and the coupling flange or tube I6 is blocked. It is,of course, obvious that, if desired, the fitting 26 of Fig. 1 may beemployed in the form of muflier shown in Fig. 5 and that the fitting 44of Fig. 5 may be employed in the form of mufiier shown in Fig. 1.

Aside from the fact that the muffler of Fig. 5 contains less metal andis therefore lighter than the mufiler in Figs. 1 to 4, it more readilylends itself to streamlining as will be readily understood when it istaken into account that it, as indicated in Fig. 6, may be provided witha sheet metal housing or sheath 46, the contour of which may vary from aso-called pure streamlined shape, such as, is approximated herein, to alesser streamlined shape according to requirements as determined, forexample, by the position that the mufiier may occupy on an airplane. Asto the sheath 46, it will be noted that its opposite ends are suitablyconnected to the head El and the ring 42, as by welding, and that thespace intermediate itself and the casing l0 may be filled with asuitable sound absorbing material 41, such as mineral wool, for thepurpose of obviating objectionable vibrating or drumming effects in thesheath itself.

In the event it becomes desirable to restrict the inletpassage area ofthe fitting 26, regardless of whether that fitting is employed in theform of mufiler of Fig. 1 or in the form of muflier of Fig. 5, suchfitting may be modified to obtain the form of fitting 26, which is shownin Figs. 7 and 8 and which is characterized by the fact that the wall ofits deflector tube 28' is so distorted as to partially close the passagetherethrough.

It is, of course, obvious that the deflector tube 28' may be completelyclosed by further distorting the wall thereof, as indicated in Fig. 9,and that when the deflector tube is thus closed the fitting 26' may beemployed, in the capacity of the fitting 44, to block the forward end ofeither the equalizing tube 18 of the muflier of Fig. 1 or the equalizingtube 18' of the mufiier of Fig. 5.

Although it is believed that the present invention may be readilyconstructed by one skilled in the art in view of the foregoingdescription, it might be well to here set forth certain of thedimensions employed in connection with a mufller constructed inaccordance with the disclosure of Figs. 1 to 4 and subjected to decibelmeter and back pressure tests which were conducted, with highlysatisfactory results, in connection with a P. 8: W. Wasp airplaneengine- Series C-rated 420 H. P. at 2000 R. P. M. The dimensions were asfollows: Casing l0--23% long, 8" I. D.; shell 2019% long, 7" O. D.;

equalizing tube |83.834" I. D., 4" O. D., 21 long as measured from itsfront end to that end of the shell nearest the outlet end of themufller; deflector tube 28-1805" I. D., 1%" 0. D., feeder tube ports 31-wide and having a combined area of 10.86 sq. in.; equalizing tube ports38- 1 /20" wide and having a combined area of 8.069 sq. in.

After testing the above dimensionally identified muffler with theequalizing tube 28 fully open, further tests were carried out with thatmufiler to determine what effect, if any, might be obtained by partiallyclosing and by completely closing the deflector tube. Partial closing ofthe deflector tube was efiected by introducing therein plug-likebushings provided with inlet passages of 1 and 1", respectively, whereascomplete closing of that tube was effected by introducing therein asolid plug.

During the above tests, which were conducted at engine speeds of 800,1000, 1200, 1400, and 1600 R. P. M., it was observed that as the inletarea of the deflector tube 28 was varied from maximum to zero, mufilingability was improved at the expense of a slight increase in backpressure, as will become apparent from the following table whereinmuffler A is the mufiier of Fig. l with fully open deflector tube,mufiier B is mufller A equipped with a defiector-tube-reducing-bushinghaving a 1 opening, mufiier C is mufiier A equipped with adeflector-tubereducing-bushing having a 1" opening and mufiler D ismufiler A with the deflector tube completely closed by a solid plug:

In view of the fact that any attempt to here describe the operation ofthe invention from a purely technical standpoint might possibly lend toconfusion, and since such technical explanation is not here required, itwill suffice to trace the paths which the exhaust traverses in passingthrough the muflier and to comment on the same wherever necessary forthe sake of clarity.

Referring to Fig. 1, it will appear that when the coupling tube It ofthe mufiler is attached to the exhaust pipe of an internal combustionengine and such engine is operated at various speeds under its ownpower, a portion of the exhaust emitted from the engine will passdirectly into the equalizing tube 18 by way of the deflector tube 28(assuming the deflector tube to be either fully open or partially open)and another portion of such exhaust will enter the equalizing tube byway of the feeder tube 35, the ported side wall area (namely the feedertube ports 31) of the feeder tube 35, the reservoir 36, and the portedside wall area (namely the equalizing tube ports 38) of the equalizingtube l8. Such exhaust as passes from the feeder tube 35 into thereservoir 36 by way of the feeder tube ports 31 will be impinginglydirected against the inner wall surface of the reservoir and whirledunder its own impetus in a whirl path along that surface in thedirection of the arrow A appearing in Fig. 4. As the exhaust is whirledalong the inner wall surface of the reservoir 36 its energy is expendednot only by reason of such factors as surface friction, but also byreason of the fact that the whirling exhaust is utilized to perform auseful work function,-namely, the setting up of an ejector action at thefeeder tube ports 31. Such ejector action is effected by reason of thepresence of the deflecting lips 40, over which the whirling exhaustpasses, and is utilized to scavenge the feeder tube 35, thus relievingthe same of internal pressure which, at least in part, accounts for thelow back pressure performance of the muffler. As the energy of thewhirling exhaust within the reservoir 36 is dissipated, such exhaustmoves into the immediately surrounding vicinity of the equalizing tubewhere it assumes, or at least approaches, a staticpressure-condition,following which it is directed under pressure into the equalizing tubel8 by Way of the equalizing tube ports 38. As the exhaust enters theequalizing tube 18 by way of its ports 38, it is whirled under its ownimpetus in a whirl path along the inner wall of the equalizing tube inthe direction of the arrow B appearing in Fig. 4. As the exhaust iswhirled along the inner wall surface of the equalizing tube I8, itsenergy is expended in the manner described in connection with thewhirling exhaust within the reservoir 36, it being observed that theexpenditure of such energy as accounts for the ejector action set up inthe vicinity of the ports 38 by the whirling exhaust passing over thedeflecting lips M is utilized to facilitate movement of exhaust from thestatic areas of the reservoir, namely, the immediately surroundingvicinity of the equalizing tube.

From the foregoing, it will be observed that the exhaust in passing fromthe feeder tube 35 into the equalizing tube [8 undergoes a cyclicchange, as will be readily appreciated when taking into account that thedirection of whirl of the exhaust within the equalizing tube I8 is indirect opposition to the direction of whirl of the exhaust within thereservoir 36. This change in direction of flow accounts, in itself, fora dissipation of energy, and therefore supplements the above mentionedenergy consuming factors which are peculiar to the present invention.Additionally it will be understood that the exhaust entering theequalizing tube l8 by way of its ports 38 is not only whirled withinthat tube, as above explained, but is also commingled with the exhaustentering that tube by Way of the deflector tube 28, with the result thatthe entire contents of the equalizing tube traverses a generally helicalpath as it proceeds toward the exit end of the muffler.

Although the foregoing description of the operation of the muffler ofFig. 1 assumes the deflector tube 28 to be either fully open orpartially open, it is believed unnecessary to describe the operation ofthat muffler if modified, as previously suggested herein, bysubstituting for its fitting 26 the fitting 44 of Fig. 5 in order toclose the forward end of the equalizing tube 18.

Moreover, it is believed that no detailed description of the operationof the muffler of Fig. 5, either as shown therein or as modified inaccordance with the suggestions previously made herein, is necessaryother than to point out that the whirling exhaust within the reservoir36 will at least tend to creep toward the larger end of the reservoir inseeking a larger or more extensive whirl path and to further point outthat the feeder tube 35 and the reservoir 36, each present aprogressively varying cross-sectional area with the result that themuifier structure, when considered in its entirety, will effectivelyextenuate vibrations over a wide range of frequencies, includingfundamentals and their harmonics.

Aside from the modifications either herein shown and described, orsuggested, it will be understood that various other changes may beresorted to without departing from the spirit of the invention or thescope of the following claims.

I claim:

1. In a muffler, an equalizing tube having a ported side wall area andadapted to carry exhaust, a feeder tube having a ported side wall areaand adapted to carry exhaust, a reservoir communicating with said tubesby way of their ported wall areas and adapted to receive exhaust fromsaid feeder tube by way of the ported wall area thereof and deliver ittosaid equalizing tube by way of its ported wall area, the inner wallsurface of said reservoir defining a closed circuitous whirl path andbeing located with relation to the ported wall area of said feeder tubeto impingingly receive exhaust issuing from that ported area, the innerwall surface of said reservoir being disposed with relation to the lineof flow of exhaust issuing from the ported wall area of said feeder tubeto direct such exhaust both incident and pursuant to impingement in aunidirectional whirl along said closed circuitous path.

2. In a mufller, an equalizing tube having a ported side wall area andadapted to carry exhaust, a feeder tube having a ported side wall area.and adapted to carry exhaust, a reservoir COIl'lmunicating with saidtubes by way of their ported wall areas and adapted to receive exhaustfrom said feeder tube by way of the ported wall area thereof and deliverit to said equalizing tube by way of its ported wall area, the innerwall surface of said equalizing tube defining a closed circuitous whirlpath and being located with relation to the ported wall area of saidequalizing tube to impingingly receive exhaust issuing from that portedarea, the inner wall surface of said equalizing tube being disposed withrelation to the line of fiow of exhaust issuing from the ported wallarea of said equalizing tube to direct such exhaust both incident andpursuant to impingement in a unidirectional whirl along said closedcircuitous path.

3. In a muffler, an equalizing tube having a ported side wall area andadapted to carry exhaust, a feeder tube having a ported side wall areaand adapted to carry exhaust, a reservoir communicating with said tubesby way of their ported wall areas and adapted to receive exhaust fromsaid feeder tube by way of the ported wall area thereof and deliver itto said equalizing tube by way of its ported wall area, the inner wallsurface of said reservoir defining a closed circuitous whirl path andbeing located with relation to the ported wall area of said feeder tubeto impingingly receive exhaust issuing from that ported area, the innerwall surface of said reservoir being disposed with relation to the lineof fiow of exhaust issuing from the ported wall area of said feeder tubeto direct such exhaust both incident and pursuant to impingement in aunidirectional whirl along said closed circuitous path, the inner wallsurface of said equalizing tube defining a closed circuitous whirl pathand being located with relation to the ported wall area of saidequalizing tube to impingingly receive exhaust issuing from that portedarea, the inner wall surface of said equalizing tube being disposed withrelation to the line of flow of exhaust issuing from the ported wallarea of said equalizing tube to direct such exhaust both incident andpursuant to impingement in a unidirectional whirl along thesecond-mentioned closed circuitous path.

4. In a muflier, an equalizing tube having a ported side wall area andadapted to carry exhaust, a feeder tube disposed in a contiguousrelation to said equalizing tube and having a ported side wall area andadapted to carry exhaust, a reservoir surrounding said equalizing tubeand communicating with said tubes by way of their ported wall areas andadapted to receive exhaust from said feeder tube by way of the portedwall area thereof and deliver it to said equalizing tube by way of itsported wall area, the inner wall surface of said reservoir defining aclosed circuitous whirl path and being located with relation to theported wall area of said feeder tube to impingingly receive exhaustissuing from that ported area, the inner wall surface of said reservoirbeing disposed with relation to the line of flow of exhaust issuing fromthe ported wall area of said feeder tube to direct such exhaust bothincident and pursuant to impingement in a unidirectional whirl alongsaid closed circuitous path.

5. In a muiiier, an equalizing tube having a ported side wall area andadapted to carry exhaust, a feeder tube disposed in a contiguousrelation to said equalizing tube and having a ported side wall area andadapted to carry exhaust, a reservoir surrounding said equalizing tubeand communicating with said tubes by way of their ported wall areas andadapted to receive exhaust from said feeder tube by way of the portedwall area thereof and deliver it to said equalizing tube by way of itsported wall area, the inner wall surface of said equalizing tubedefining a closed circuitous whirl path and being located with relationto the ported wall area of said equalizing tube to impingingly receiveexhaust issuing from that ported area, the inner wall surface of saidequalizing tube being disposed with relation to the line of flow ofexhaust issuing from the ported wall area of said equalizing tube todirect such exhaust both incident and pursuant to impingement in aunidirectional whirl along said closed circuitous path.

6, In a mufiier, an equalizing tube having a ported side wall area andadapted to carry exhaust, a feeder tube disposed ina contiguous relationto said equalizing tube and having a ported side wall area and adaptedto carry exhaust, a reservoir surrounding said equalizing tube andcommunicating with said tubes by way of their ported wall areas andadapted to receive exhaust from said feeder tube by way of the portedwall area thereof and delivery it to said equalizing tube by way of itsported wall area, the inner wall surface of said reservoir defining aclosed circuitous whirl path and being located with relation to theported wall area of said feeder tube to impingingly receive exhaustissuing from that ported area, the inner wall surface of said reservoirbeing disposed with relation to the line of flow of exhaust issuing fromthe ported wall area of said feeder tube to direct such exhaust bothincident and pursuant to impingement in a unidirectional aoeaooo whirlalong said closed circuitous path, the inner wall surface of saidequalizing tube defining a closed circuitous whirl path and beinglocated with relation to the ported wall area of said equalizing tube toimpingingly receive exhaust issuing from that ported area, the innerwall surface of said equalizing tube being disposed with relation to theline of flow of exhaust issuing from the ported wall area of saidequalizing tube to direct such exhaust both incident and pursuant toimpingement in a unidirectional whirl along the second-mentioned closedcircuitous path.

'7. In a muiiier, an equalizing tube closed at one end and having aported side wall area and adapted to carry exhaust, a feeder tube havinga ported side Wall area and adapted to carry exhaust, a reservoircommunicating with :aid tubes by way of their ported wall areas andadapted to receive exhaust from said feeder tube by way of the portedwall area thereof and deliver it to said equalizing tube by way of itsported wall area, the inner wall surface of said reservoir defining aclosed circuitous whirl path and being located with relation to theported Wall area of said feeder tube to impingingly receive exhaustissuing from that ported area, the inner wall surface of said reservoirbeing disposed with relation to the line of flow of exhaust issuing fromthe ported wall area of said feeder tube to direct such exhaust bothincident and pursuant to impingement in a unidirectional whirl alongsaid closed circuitous path.

8. In a muffler, an equalizing tube closed at one end and having aported side wall area and adapted to carry exhaust, a feeder tube havinga ported side wall area and adapted to carry exhaust, a reservoircommunicating with said tubes by way of their ported wall areas andadapted to receive exhaust from said feeder tube by way of the portedwall area thereof and deliver it to said equalizing tube by way of itsported wall area, the inner wall surface of said equalizing tubedefining a closed circuitous whirl path and being located with relationto the ported wall area of said equalizing tube to impingingly receiveexhaust issuing from that ported area, the inner wall surface of saidequalizing tube being disposed with relation to the line of flow ofexhaust issuing from the ported wall area of said equalizing tube todirect such exhaust both incident and pursuant to impingement in aunidirectional whirl along said closed circuitous path.

9. In a mufiier, an equalizing tube closed at one end and having aported side wall area and adapted to carry exhaust, a feeder tube havinga ported side wall area and adapted to carry exhaust, a reservoircommunicating with said tubes by way of their ported wall areas andadapted to receive exhaust from said feeder tube by way of the portedwall area thereof and deliver it to said equalizing tube by way of itsported wall area, the inner wall surface of said reservoir defining aclosed circuitous whirl path and being located with relation to theported wall area of said feeder tube to impingingly receive exhaustissuing from that ported area, the inner wall surface of said reservoirbeing disposed with relation to the line of flow of exhaust issuing fromthe ported wall area of said feeder tube to direct such exhaust bothincident and pursuant to impingement in a unidirectional whirl alongsaid closed circuitous path, the inner wall surface of said equalizingtube defining a closed circuitous whirl path and being located withrelation to the ported wall area of said equalizing tube to impinginglyreceive exhaust issuing from that ported area, the inner wall surface ofsaid equalizing tube being disposed with relation to the line of flow ofexhaust issuing from the ported wall area of said equalizing tube todirect such exhaust both incident and pursuant to impingement in aunidirectional whirl along the second-mentioned closed circuitous path.

10. In a muffler, an equalizing tube closed at one end and having aported side wall area and adapted to carry exhaust, a feeder tubedisposed in a contiguous relation to said equalizing tube and having aported side wall area and adapted to carry exhaust, a reservoirsurrounding said equalizing tube and communicating with said tubes bywayof their ported wall areas and adapted to receive exhaust from saidfeeder tube by way of the ported wall area thereof and deliver it tosaid equalizing tube by way of its ported wall area, the inner wallsurface of said reservoir defining a closed circuitous whirl path andbeing located with relation to the ported wall area of said feeder tubeto impingingly receive exhaust issuing from that ported area, the innerwall surface of said reservoir being disposed with relation to the lineof flow of exhaust issuing from the ported wall area of said feeder tubeto direct such exhaust both incident and pursuant to impingement in aunidirectional whirl along said closed circuitous path.

11. In a muffler, an equalizing tube closed at one end and having aported side wall area and adapted to carry exhaust, a feeder tubedisposed in a contiguous relation to said equalizing tube and having aported side wall area and adapted to carry exhaust, a reservoirsurrounding said equalizing tube and communicating with said tubes byway of their ported wall areas and adapted to receive exhaust from saidfeeder tube by way of the ported wall area thereof and deliver it tosaid equalizing tube by way of its ported wall area, the inner wallsurface of said equalizing tube defining a closed circuitous whirl pathand being located with relation to the ported wall area of saidequalizing tube to impingingly receive exhaust issuing from that portedarea, the inner wall surface of said equalizing tube being disposed withrelation to the line of fiow of exhaust issuing from the ported wallarea of said equalizing tube to direct such exhaust both incident andpursuant to impingement in a unidirectional whirl along said closedcircuitous path.

12. In a muffler, an equalizing tube closed at one end and having aported side wall area and adapted to carry exhaust, a feeder tubedisposed in a contiguous relation to said equalizing tube and having aported side wall area and adapted to carry exhaust, a reservoirsurrounding said equalizing tube and communicating with said tubes byway of their ported wall areas and adapted to receive exhaust from saidfeeder tube by way of the ported wall area thereof and deliver it tosaid equalizing tube by way of its ported wall area, the inner wallsurface of said reservoir defining a closed circuitous whirl path andbeing located with relation to the ported wall area of said feeder tubeto impingingly receive exhaust issuing from that ported area, the innerwall surface of said reservoir being disposed with relation to the lineof flow of exhaust issuing from the ported wall area of said feeder tubeto direct such exhaust both incident and pursuant to impingement in aunidirectional whirl along said closed circuitous path, the inner wallsurface of said equalizing tube defining a closed circuitous whirl pathand being located with relation to the ported wall area of saidequalizing tube to impingingly receive exhaust issuing from that portedarea, the inner wall surface of said equalizing tube being disposed withrelation to the line of flow of exhaust issuing from the ported wallarea of said equalizing tube to direct such exhaust both incident andpursuant to impingement in a unidirectional whirl along thesecondmentioned closed circuitous path.

13. In a mufller, an equalizing tube having a ported side wall area andadapted to carry exhaust, a feeder tube surrounding said equalizing tubeand having a ported side wall area and adapted to carry exhaust, areservoir communicating with said tubes by way of their ported wallareas and adapted to receive exhaust from said feeder tube by way of theported wall area thereof and deliver it to said equalizing tube by wayof its ported wall area, the inner wall surface of said reservoirdefining a closed circuitous whirl path and being located with relationto the ported wall area of said feeder tube to impingingl'y receiveexhaust issuing from that ported area, the inner wall surface of saidreservoir being disposed with relation to the line of flow of exhaustissuing from the ported Wall area of said feeder tube to direct suchexhaust both incident and pursuant to impingement in a unidirectionalwhirl along said closed circuitous path.

14. In a mufller, an equalizing tube having a ported side wall area andadapted to carry exhaust, a feeder tube surrounding said equalizing tubeand having a ported side wall area and adapted to carry exhaust, areservoir communicating with said tubes by way of their ported wallareas and adapted to receive exhaust from said feeder tube by way of theported wall area thereof and deliver it to said equalizing tube by wayof its ported wall area, the inner wall surface of said equalizing tubedefining a closed circuitous whirl path and being located with relationto the ported wall area of said equalizing tube to impingingly receiveexhaust issuing from that ported area, the inner wall surface of saidequalizing tube being disposed with relation to the line of flow ofexhaust issuing from the ported wall area of said equalizing tube todirect such exhaust both incident and pursuant to impingement in aunidirectional whirl along said closed circuitous path.

15. In a muiiler, an equalizing tube having a ported side wall area andadapted to carry exhaust, a feeder tube surrounding said equalizing tubeand having a ported side wall area and adapted to carry exhaust, areservoir communicating with said tubes by way of their ported wallareas and adapted to receive exhaust from said feeder tube by way of theported wall area thereof and deliver it to said equalizing tube by wayof its ported wall area, the inner wall surface of said reservoirdefining a closed circuitous whirl path and being located with relationto the ported wall area of said feeder tube to impingingly receiveexhaust issuing from that ported area, the inner wall surface of saidreservoir being disposed with relation to the line of flow of exhaustissuing from the ported wall area of said feeder tube to direct suchexhaust both incident and pursuant to impingement in a undirectionalwhirl along said closed circuitous path, the inner wall surface of saidequalizing tube defining a closed circuitous whirl path and beinglocated with relation to the ported wall area of said equalizing tube toimpingingly receive exhaust issuing from that ported area, the innerwall surface of said equalizing tube being disposed with relation to theline of flow of exhaust issuing from the ported wall area of saidequalizing tube to direct such exhaust both incident and pursuant toimpingement in a unidirectional whirl along the secondmentioned closedcircuitous path.

16. In a mufiler, an equalizing tube having a ported side wall area andadapted to carry exhaust, a feeder tube surrounding and disposed in acontiguous relation to said equalizing tube and having a ported sidewall area and adapted to carry exhaust, a reservoir surrounding saidequalizing tube and communicating with said tubes by way of their portedwall areas and adapted to receive exhaust from said feeder tube by wayof the ported wall area thereof and deliver it to said equalizing tubeby way of its ported wall area, the inner wall surface of said reservoirdefining a closed circuitous whirl path and being located with relationto the ported wall area of said feeder tube to impingingly receiveexhaust issuing from that ported area, the inner wall surface of saidreservoir being disposed with relation to the line of flow of exhaustissuing from the ported wall area of said feeder tube to direct suchexhaust both incident and pursuant to impingement in a unidirectionalwhirl along said closed circuitous path.

17. In a muiiler, an equalizing tube having a ported side wall area andadapted to carry exhaust, a feeder tube surrounding and disposed in acontiguous relation to said equalizing tube and having a ported sidewall area and adapted to carry exhaust, a reservoir surrounding saidequalizing tube and communicating with said tubes by way of their portedwall areas and adapted to receive exhaust from said feeder tube by wayof the ported Wall area thereof and deliver it to. said equalizing tubeby way of its ported wall area, the inner wall surface of saidequalizing tube defining a closed circuitous whirl path and beinglocated with relation to the ported wall area of said equalizing tube toimpingingly receive exhaust issuing from that ported area, the innerwall surface of said equalizing tube being disposed with relation to theline of flow of exhaust issuing from the ported wall area of saidequalizing tube to direct such exhaust both incident and pursuant toimpingement in a unidirectional whirl along said closed circuitous path.

18. In a mufiier, an equalizing tube having a ported side wall area andadapted to carry exhaust, a feeder tube surrounding and disposed in acontiguous relation to said equalizing tube and having a ported sidewall area and adapted to carry exhaust, a reservoir surrounding saidequalizing tube and communicating with said tubes by way of their portedwall areas and adapted to receive exhaust from said feeder tube by Wayof the ported Wall area thereof and deliver it to said equalizing tubeby Way of its ported wall area, the inner wall surface of said reservoirdefining a closed circuitous whirl path and being located with relationto the ported wall area of said feeder tube to impingingly receiveexhaust issuing from that ported area,the inner wall surface of saidreservoir being disposed with relation to the line of flow of exhaustissuing from the ported wall area of said feeder tube to direct suchexhaust both incident and pursuant to impingement in a unidirectionalwhirl along said closed circuitous path, the inner wall surface of saidequalizing tube defining a, closed circuitous whirl path and beinglocated with relation to the ported wall area of said equalizing tube toimpingingly receive exhaust issuing from that ported area, the innerwall surface of said equalizing tube being disposed with relation to theline of fiow of exhaust issuing from the ported wall area of saidequalizing tube to direct such exhaust both incident and pursuant toimpingement in a unidirectional whirl along the secondmentioned closedcircuitous path. 1

19. In a muliier, an equalizing tube having ported side wall area andadapted to carry exhaust, a feeder tube having a ported side wall areaand adapted to carry exhaust, a reservoir communicating with said tubesby way of their ported wall areas and adapted to receive exhaust fromsaid feeder tube by way of the ported wall area thereof and deliver itto saidequalizing tube by way of its ported wall area, the inner wallsurface of said reservoir defining a closed circuitous whirl path andbeing located with relation to the ported wall area of said feeder tubeto impingingly receive exhaust issuing from that ported area, the innerwall surface of said reservoir being disposed with relation to thelineof fiow of exhaust issuing from the ported wall area of said feedertube to direct such exhaust both incident and pursuant to impingement ina unidirectional whirl along said closed circuitous path, and meansfunctioning in response to movement of exhaust in said whirl path withinsaid reservoir for producing an ejector action with reference to saidfeeder tube.

20. In a muffler, an equalizing tube having a ported side wall area andadapted to carry exhaust, a feeder tube having a ported side wall areaand adapted to carry exhaust, a reservoir communicating with said tubesby way of their ported wall areas and adapted to receive exhaust fromsaid feeder tube by way of the ported wall area thereof and deliver itto said equalizing tube by way of its ported wall area, the inner wallsurface of said equalizing tube defining a closed circuitous whirl pathand being located with relation to the ported wall area of saidequalizing tube to impingingly receive exhaust issuing from that portedarea, the inner wall surface of said equalizing tube being disposed withrelation to the line of fiow of exhaust issuing from the ported wallarea of said equalizing tube to direct such exhaust both incident andpursuant to impingement in a unidirectional whirl along said closedcircuitous path, and means functioning in response to movement ofexhaust in said whirl path within said equalizing tube for producing anejector action with reference to said reservoir.

21. In a mufiler, an equalizing tube having a ported side wall area andadapted to carry exhaust, a feeder tube having a ported side wall areaand adapted to carry exhaust, a reservoir communicating with said tubesby way of their ported wall areas and adapted to receive exhaust fromsaid feeder tube by way of the ported wall area thereof and deliver itto said equalizing tube 1 wall surface of said equalizing tubedefinining a closed circuitous whirl path and being located withrelation to the ported wall area of said equalizing tube to impinginglyreceive exhaust issuing from that ported area, the inner wall surface ofsaid equalizing tube being disposed with relation to the line of flow ofexhaust issuing from the ported wall area of said equalizing tube todirect such exhaust both incident and pursuant to impingement in aunidirectional whirl along the second-mentioned closed circuitous path,and means functioning in response to movement of exhaust in said whirlpaths within said reservoir and within said equalizing tube forproducing an ejector action with reference to said feeder tube and saidreservoir.

22. In a muflier, an equalizing tube having a ported side wall area andadapted to carry exhaust, a feeder tube having a ported side wall areaand adapted to carry exhaust, a reservoir communicating with said tubesby way of their ported wall areas and adapted to receive exhaust fromsaid feeder tube by way of the ported wall area thereof and deliver itto said equalizing tube by way of its ported wall area, the inner wallsurface of said reservoir defining a closed circuitous whirl path andbeing located with relation to the ported wall area of said feeder tubeto impingingly receive exhaust issuing from that ported area, the innerwall surface of said reservoir being disposed with relation to the lineof flow of exhaust issuing from the ported wall area of said feeder tubeto direct such exhaust both incident and pursuant to impingement in aunidirectional whirl along said closed circuitous path, and meansfunctioning in response to movement of exhaust in said whirl path withinsaid reservoir for producing an ejector action with reference to saidfeeder tube, said ejector means including deflecting lips associatedwith said ported area of said feeder tube.

23. In a muffler, an equalizing tube having a ported side wall area andadapted to carry exhaust, a feeder tube having a ported side wall areaand adapted to carry exhaust, a reservoir communicating with said tubesby way of their ported wall areas and adapted to receive exhaust fromsaid feeder tube by way of the ported wall area thereof and deliver itto said equalizing tube by way of its ported wall area, the inner wallsurface of said equalizing tube defining a closed circuitous whirl pathand being located with relation to the ported wall area of saidequalizing tube to impingingly receive exhaust issuing from that portedarea, the inner wall surface of said equalizing tube being disposed withrelation to i the line of flow of exhaust issuing from the ported wallarea of said equalizing tube to direct such exhaust both incident andpursuant to impingement in a unidirectional whirl along said closedcircuitous path, and means functioning in response to movement ofexhaust in said whirl path within said equalizing tube for producing anejector action with reference to said reservoir, said ejector meansincluding deflecting lips associated with said ported area of saidequalizing tube.

24. In a muffler, an equalizing tube having a ported side wall area andadapted to carry exhaust, a feeder tube having a ported side wall areaand adapted to carry exhaust, a reservoir communicating with said tubesby way of their ported Wall areas and adapted to receive exhaust fromsaid feeder tube by way of the ported wall area thereof and deliver itto said equalizing tube by way of its ported wall area, the inner wallsurface of said reservoir defining a closed circuitous whirl path andbeing located with relation to the ported wall area of said feeder tubeto impingingly receive exhaust issuing from that ported area, the innerwall surface of said reservoir being disposed with relation to the lineof flow of exhaust issuing from the ported wall area of said feeder tubeto direct such exhaust both incident and pursuant to impingement in aunidirectional whirl along said closed circuitous path, the inner wallsurface of said equalizing tube defining a closed circuitous whirl pathand being located with relation to the ported wall area of saidequalizing tube to impingingly receive exhaust issuing from that portedarea, the inner wall surface of said equalizing tube being disposed withrelation to the line of flow of exhaust issuing from the ported wallarea of said equalizing tube to direct such exhaust both incident andpursuant to impingement in a unidirectional whirl along thesecond-mentioned closed circuitous path, and means functioning inresponse to movement of exhaust in said whirl paths within saidreservoir and within said equalizing tube for producing an ejectoraction with reference to said feeder tube and said reservoir, saidejector means including deflecting lips associated with said portedareas of said feeder tube and said equalizing tube.

25. In a muffler, means for dividing a column of exhaust, an equalizingtube having a ported side wall area and adapted to convey one portion ofthe divided exhaust, a feeder tube having a ported side wall area andadapted to carry another portion of the divided exhaust, a reservoircommunicating with said tubes by way of their ported wall areas andadapted to receive exhaust from said feeder tube by way of the portedWall area thereof and deliver it to said equalizing tube by way of itsported wall area, the inner wall surface of said reservoir defining aclosed circuitous whirl path and being located with relation to theported wall area of said feeder tube to impingingly receive exhaustissuing from that ported area, the inner wall surface of said reservoirbeing disposed with relation to the line of flow of exhaust issuing fromthe ported wall area of said feeder tube to direct such exhaust bothincident and pursuant to impingement in a unidirectional whirl alongsaid closed circuitous path.

26. In a muffler, means for dividing a column of exhaust, an equalizingtube having a ported side wall area and adapted to convey one portion ofthe divided exhaust, a feeder tube having a ported side wall area andadapted to carry another portion of the divided exhaust, a reservoircommunicating with said tubes by way of their ported wall areas andadapted to receive exhaust from said feeder tube by way of the portedwall area thereof and deliver it to said equalizing tube by way of itsported wall area, the inner wall surface of said equalizing tubedefining a closed circuitous whirl path and being located with relationto the ported wall area of said equalizing tube to impingingly receiveexhaust issuing from that ported area, the inner wall surface of saidequalizing tube being disposed with relation to the line of flow ofexhaust issuing from the ported wall area of said equalizing tube todirect such exhaust both incident and pursuant to impingement in aunidirectional whirl along said closed circuitous path.

27. In a mulller, means for dividing a column of exhaust, an equalizingtube having a ported side wall area and adapted to convey one portion ofthe divided-exhaust, a feeder tube having a ported side wall area andadapted to carry another portion of the divided exhaust, a reservoircommunicating with said tubes by way of their ported wall areas andadapted to receive exhaust from said feeder tube by way of the portedwall area thereof and deliver it to said equalizing tube by way of itsported wall area,'

the inner Wall surface of said reservoir defining a closed circuitouswhirl path and being located with relation to the ported wall area ofsaid feeder tube to impingingly receive exhaust issuing from that portedarea, the inner wall surface of said reservoir being disposed withrelation to the line of flow of exhaust issuing from the ported wallarea of said feeder tube to direct such exhaust both incident andpursuant to impingement in a unidirectional whirl along said closedcircuitous path, the inner wall surface of said equalizing tube defininga closed circuitous whirl path and being located with relation to theported wall area of said equalizing tube to impingingly receive exhaustissuing from that ported area, the inner wall surface of said equalizingtube being disposed with relation to the line of flow of exhaust issuingfrom the ported wall area of said equalizing tube to direct such exhaustboth incident and pursuant to impingement in a unidirectional whirlalong the second-mentioned closed circuitous path.

28. In a muffler of the type including a casing, an equalizing unitdisposed within said cas ing and comprising an equalizing tube having aported side wall area, a reservoir surrounding said equalizing tube andincluding a shell forming with said casing a feeder tube and serving asa feeder tube wall, said feeder tube wall having a ported area by way ofwhich exhaust is delivered from said feeder tube into said reservoir tobe thereafter delivered into said equalizing tube by way of its portedwall area, the inner wall surface of said shell defining a closedcircuitous whirl path and being located with relation to the ported areaof said feeder tube wall to impingingly receive exhaust issuing fromthat ported area, the inner wall surface of said shell being disposedwith relation to the line of flow of exhaust issuing from the portedarea of said feeder tube wall to direct such exhaust both incident andpursuant to impingement in a unidirectional whirl along said closedcircuitous path.

29. In a muflier of the type including a casing, an equalizing unitdisposed within said casing and comprising an equalizing tube having aported side wall area, a reservoir surrounding said equalizing tube andincluding a shell forming with said casing a feeder tube and serving asa feeder tube wall, said feeder tube wall having a ported area by way ofwhich exhaust is delivered from said feeder tube into said reservoir tobe thereafter delivered into said equalizing tube-by way of its portedwall area, the inner wall surface of said equalizing tube defining aclosed circuitous whirl path and being located with relation to theported wall area of said equalizing tube to impingingly receive exhaustissuing from that ported area, the inner wall surface of said equalizingtube being disposed with relation to the line of flow of exhaust issuingfrom the ported wall area of said equalizing tube to direct such exhaustboth incident and pursuant to impingement in a unidirectional whirlalong said closed circuitous path.

30. In a muiiier of the type including a casing, an equalizing unitdisposed within 'said casing and comprising an equalizing tube having aported side wall area, a reservoir surrounding said equalizing tube andincluding a shell forming with said casing a feeder tube and serving asa feeder tube wall, said feeder tube wall having a ported area by way ofwhich exhaust is delivered from said feeder tube into said reservoir tobe thereafter delivered into said equalizing tube by way of its portedwall area, the inner wall surface of said shell defining a closedcircuitous whirl path and being located with relation to the ported areaof said feeder tube wall to impingingly receive exhaust issuing fromthat ported area, the inner wall surface of said shell being disposedwith relation to the line of flow of exhaust issuing from the portedarea of said feeder tube wall to direct such exhaust both incident andpursuant to impingement in a unidirectional whirl along said closedcircuitous path, the inner wall surface of said equalizing tube defininga closed circuitous whirl path and being located with relation to theported wall area of said equalizing tube to impingingly receive exhaustissuing from that ported area, the inner wall surface of said equalizingtube being disposed with relation to the line of fiow of exhaust issuingfrom the ported wall area of said equalizing tube to direct such exhaustboth incident and pursuant to impingement in a unidirectional whirlalong the second-named closed circuitous path.

31. In a muiiier of the type including a casing, an equalizing unitdisposed within said casing and comprising an equalizing tube having aported side wall area, a reservoir surrounding said equalizing tube andincluding a shell forming with said casing a feeder tube and serving asa feeder tube wall, said feeder tube wall having a plurality of slotsextending lengthwise of the same and arranged in a contiguous relationto each other and constituting feeder tube ports by way of which exhaustis delivered from said feeder tube into said reservoir to be thereafterdelivered into said equalizing tube by way of its ported wall area, theinner wall surface of said shell defining a closed, circuitous whirlpath and being located with relation to said feeder tube ports toimpingingly receive exhaust issuing from such ports, the inner wallsurface of said shell being disposed with relation to the line of flowof exhaust issuing from said feeder tube ports to direct such exhaustboth incident and pursuant to impingement in a unidirectional whirlalong said closed circuitous path.

32. In a muflier of the type including a casing, an equalizing unitdisposed within said casing and comprising an equalizing tube having itswall provided with a plurality of slots extending lengthwise of the sameand arranged in a contiguous relation to :each other and serving asequalizing tube ports, a reservoir surrounding said equalizing tubeandincluding a shell forming with said casinga feeder tube and serving as afeeder tube wall, said feeder tube wall having a ported area by way ofwhich exhaust is delivered from said feeder tube into said reservoir tobe thereafter delivered into said equalizing tube by way of saidequalizing tube ports, the inner wall surface of said equalizing tubedefining a closed circuitous whirl path and being located with relationto said equalizing tube ports to impingingly receive exhaust issuingfrom such ports, the inner wall surface of said equalizing tube beingdisposed with relation to the line of flow of exhaust issuing from saidequalizing tube ports to direct such exhaust both incident and pursuantto impingement in a unidirectional whirl along said closed circuitouspath.

33. In a muiiier of the type including a casing, an equalizing unitdisposed within said casing and comprising an equalizing tube having itswall provided with a plurality of slots extending lengthwise of the sameand arranged in a contiguous relation to each other and serving asequalizing tube ports, a reservoir surrounding said equalizing tube andincluding a shell forming with said casing a feeder tube and serving asa feeder tube wall, said feeder tube wall having a plurality of slotsextending lengthwise'of the same and arranged in a contiguous relationto each other and constituting feeder tube ports by way of which exhaustis delivered from said feeder tube into said reservoir to be thereafterdelivered into said equalizing tube by way of said equalizing tubeports, the inner wall surface of said shell defining a closed circuitouswhirl path and being located with relation to said feeder tube ports toimpingingly receive exhaust issuing from such ports, the inner wallsurface of said shell being disposed with relation to the line of flow-of exhaust issuing from said feeder tube ports to direct such exhaustboth incident and pursuant to impingement in a unidirectional whirlalong said closed circuitous path, the inner wall surface of saidequalizing tube defining a closed circuitous whirl path and beinglocated with relation to said equalizing tube ports to impinginglyreceive exhaust issuing from such ports, the inner wall surface of saidequalizing tube being disposed with relation to the line of flow ofexhaust issuing from said equalizing tube ports to direct such exhaustboth incident and pursuant to impingement in a unidirectional whirlalong the second-named closed circuitous path. Y

34. In a muiller, means for dividing a column of exhaust, an equalizingtube having a ported side-wall area and adapted to convey one portion ofthe divided exhaust, a feeder tube having a ported side-wall area andadapted to convey another portion of the divided exhaust, a reservoircommunicating with said tubes by way of their ported wall areas andadapted to receive exhaust from said feeder tube by way of its portedwall area and to deliver such exhaust to said equalizing tube by way ofits ported wall area, and deflector means for so directing exhaust fromsaid feeder tube into said reservoir as to there impart to itself awhirling action.

35. Ina muii'ier, means for dividing a column of exhaust, an equalizingtube having a ported side-wall area and adapted to convey one portion ofthe divided exhaust, a feeder tube having a ported side-wall area andadapted to convey another portion of the divided exhaust, a reservoircommunicating with said tubes by way of their ported wall areas andadapted to receive exhaust from said feeder tube by way of its portedwall area and to deliver such exhaust to said equalizing tube by way ofits ported wall area, and deflector means for so directing exhaustpassing from said reservoir into said equalizlng tube as to there imparta whirling action to itself and to said one portion of the dividedexhaust.

36. In a mufller, means for dividing a column of exhaust, an equalizingtube having a ported side-wall area and adapted to convey one portion ofthe divided exhaust. a feeder tube having a ported side-wall area andadapted to convey another portion of the divided exhaust, a reservoircommunicating with said tubes by way of their ported wall areas andadapted to receive exhaust from said feeder tube by way of its portedwall area and to deliver such exhaust to said equalizing tube by way ofits ported wall area, deflector means for so directing exhaust from saidfeeder tube into said reservoir as to there impart to itself a whirlingaction, and deflector means for so directing exhaust passing from saidreservoir into said equalizing tube as to there impart a whirling actionto itself and to said one portion of the divided exhaust.

WILLIAMC. MILES.

